Safe Collision and Clamping Reaction for Parallel Robots During Human-Robot Collaboration

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Details

Original languageEnglish
Title of host publication2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)
Pages5966-5973
Number of pages8
ISBN (electronic)978-1-6654-9190-7
Publication statusPublished - 2023

Publication series

NameKey-title Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems
ISSN (Print)2153-0858
ISSN (electronic)2153-0866

Abstract

Parallel robots (PRs) offer the potential for safe human-robot collaboration because of their low moving masses. Due to the in-parallel kinematic chains, the risk of contact in the form of collisions and clamping at a chain increases. Ensuring safety is investigated in this work through various contact reactions on a real planar PR. External forces are estimated based on proprioceptive information and a dynamics model, which allows contact detection. Retraction along the direction of the estimated line of action provides an instantaneous response to limit the occurring contact forces within the experiment to 70 N at a maximum velocity of 0.4 m/s. A reduction in the stiffness of a Cartesian impedance control is investigated as a further strategy. For clamping, a feedforward neural network (FNN) is trained and tested in different joint angle configurations to classify whether a collision or clamping occurs with an accuracy of 80%. A second FNN classifies the clamping kinematic chain to enable a subsequent kinematic projection of the clamping joint angle onto the rotational platform coordinates. In this way, a structure opening is performed in addition to the softer retraction movement. The reaction strategies are compared in real-world experiments at different velocities and controller stiffnesses to demonstrate their effectiveness. The results show that in all collision and clamping experiments the PR terminates the contact in less than 130 ms.

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Cite this

Safe Collision and Clamping Reaction for Parallel Robots During Human-Robot Collaboration. / Mohammad, Aran; Schappler, Moritz; Habich, Tim-Lukas et al.
2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS). 2023. p. 5966-5973 (Key-title Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems).

Research output: Chapter in book/report/conference proceedingConference contributionResearchpeer review

Mohammad, A, Schappler, M, Habich, T-L & Ortmaier, T 2023, Safe Collision and Clamping Reaction for Parallel Robots During Human-Robot Collaboration. in 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS). Key-title Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems, pp. 5966-5973. https://doi.org/10.48550/arXiv.2308.09656, https://doi.org/10.1109/iros55552.2023.10341581
Mohammad, A., Schappler, M., Habich, T.-L., & Ortmaier, T. (2023). Safe Collision and Clamping Reaction for Parallel Robots During Human-Robot Collaboration. In 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (pp. 5966-5973). (Key-title Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems). https://doi.org/10.48550/arXiv.2308.09656, https://doi.org/10.1109/iros55552.2023.10341581
Mohammad A, Schappler M, Habich TL, Ortmaier T. Safe Collision and Clamping Reaction for Parallel Robots During Human-Robot Collaboration. In 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS). 2023. p. 5966-5973. (Key-title Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems). doi: 10.48550/arXiv.2308.09656, 10.1109/iros55552.2023.10341581
Mohammad, Aran ; Schappler, Moritz ; Habich, Tim-Lukas et al. / Safe Collision and Clamping Reaction for Parallel Robots During Human-Robot Collaboration. 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS). 2023. pp. 5966-5973 (Key-title Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems).
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abstract = "Parallel robots (PRs) offer the potential for safe human-robot collaboration because of their low moving masses. Due to the in-parallel kinematic chains, the risk of contact in the form of collisions and clamping at a chain increases. Ensuring safety is investigated in this work through various contact reactions on a real planar PR. External forces are estimated based on proprioceptive information and a dynamics model, which allows contact detection. Retraction along the direction of the estimated line of action provides an instantaneous response to limit the occurring contact forces within the experiment to 70 N at a maximum velocity of 0.4 m/s. A reduction in the stiffness of a Cartesian impedance control is investigated as a further strategy. For clamping, a feedforward neural network (FNN) is trained and tested in different joint angle configurations to classify whether a collision or clamping occurs with an accuracy of 80%. A second FNN classifies the clamping kinematic chain to enable a subsequent kinematic projection of the clamping joint angle onto the rotational platform coordinates. In this way, a structure opening is performed in addition to the softer retraction movement. The reaction strategies are compared in real-world experiments at different velocities and controller stiffnesses to demonstrate their effectiveness. The results show that in all collision and clamping experiments the PR terminates the contact in less than 130 ms.",
author = "Aran Mohammad and Moritz Schappler and Tim-Lukas Habich and Tobias Ortmaier",
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AU - Mohammad, Aran

AU - Schappler, Moritz

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